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| Reply To: | TechNet E-Mail Forum. |
| Date: | Thu, 2 Dec 1999 12:23:18 -0500 |
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One word of caution on using thieving or copper fill on internal layers, at
high frequency (1GHz+) this can become part of the conductive path if it is
left floating. In that design arena it is better to tie the copper fill to
either the power or return plane at very short intervals (>1/20 of the wave
length) to reduce spurious noise signals.
Jeffrey A. McGlaughlin
PCB Designer
Battelle Memorial Institute
Columbus Ohio
[log in to unmask]
-----Original Message-----
From: John Anselmo [SMTP:[log in to unmask]]
Sent: Thursday, 02 December, 1999 09:51
To: [log in to unmask]
Subject: Re: [TN] Balanced construction....
Barbara, the answer is yes. It does help. If we see a need
for
"copper thieving" to prevent warping, we end up calling the
customer.
This always causes delays.
As far as the type, we use a 50 mil square on 100 mil
centers and
keep the square anywhere from 20 to 50 mils from any feature.
John Anselmo
Hadco - Tech Center Austin
512-246-5616
______________________________ Reply Separator
_________________________________
Subject: [TN] Balanced construction....
Author: Barbara Burcham <[log in to unmask]> at smtplink-hadco
Date: 12/2/99 8:51 AM
Hey Ya'll,
The subject has come up....why add copper to signal layers in
a
multilayer board if it has no electrical function?
I am in the habit of filling open areas with copper to prevent board
warpage. This does work, doesn't it?
Should copper fill be solid or hatched? Or does it matter?
Help a designer/Help an engineer.
Thanks,
Barbara J. Burcham, CID
PCB Designer
Fairfield Industries
Sugar Land, TX 77478
281-275-7687 Work
281-275-7550 Fax
[log in to unmask]
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